<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        function isOu(num){
            // 返回：判断num是否偶数
            return num % 2 == 0;
        }
        // 定义result变量给函数isOu值为2
        var result = isOu(2);
        console.log("result =" + result );

        // 定义一个函数，根据半径算圆面积：
        function yuanS(r){
            return 3.14*r*r;
        }
        result = yuanS(12);
        console.log("圆的面积 =" +result);


    </script>


</head>
<body>

</body>
</html>